In the context of advocating energy conservation and environmental protection nowadays, more and more people are selecting bicycle riding as a means of travel or as a way of physical exercise. However, riding can pose certain potential safety hazards when no adequate protective articles are provided. Helmet is hence one of the common protective articles for the rider, which can protect the head of the rider from external injuries. The shell of the helmet is usually made of high-strength materials like metals, engineering plastics, aramid fiber and so forth, through the deformation of which a majority of the impact force would be absorbed, so as to alleviate the injuries to the head and protect the safety and health of the rider. The problem is that, these helmets only provide passive protection, that is, provide protection only after the occurrence of a safety accident. It means that they can provide no prevention against safety accidents in advance; particularly, during the night or on a dark road, given that the bicycles are lighter and mostly do not have a head lamp or steering lamp, it makes it very difficult for others on the road to perceive the position or steering intention of the rider. As a result, damages may be caused by motor vehicles to the rider.